There is a need for planting apparatus which will efficiently and effectively deposit seeds or other particulate material such as fertilizers, insecticides and/or herbicides in the ground without requiring tilling of the ground prior to planting. Ground covered by stubble from previous crops is conveniently tilled before replanting and this is a time-consuming and expensive process. Considerable savings can be realized if such fields can be planted without pre-tilling.
There have been attempts in the past to create equipment that will achieve the aforementioned results. Single disc openers appear in U.S. Pat. Nos. 1,940,273; 2,869,489; 2,920,587; and 4,031,834 and in Canadian Patent No. 1,294,177. Each of these openers and planters operates on the principle of cutting a thin furrow in the ground, planting seed and/or fertilizer in the furrow and then closing the furrow thereafter. The structure and operation of these devices has left much to be desired when it comes to efficiency and cost of construction and operation.
The present invention overcomes the problems of the prior art by providing apparatus that will effectively and simultaneously cut a narrow (about 11/5" wide) furrow in the ground to a controlled depth, drive seed or other particulate material under air pressure into the furrow just created, tamp the deposited material firmly into the earth, and then close the furrow as the apparatus moves along. A plurality of parallel furrows can be created and planted by mounting a corresponding plurality of the air drill assemblies of the invention to laterally extending implement mounting bars which are towed behind a tractor. The width of the implement mounting bars is determined only by the towing capacity of the tractor and the size of the field to be planted. Folding mounting bars can be used for very wide applications.
In its broadest form the present invention may be considered as providing air drill apparatus for towing behind a tractor and for placing seed or other particulate material in the ground, comprising: wheeled implement means adapted to be towed behind the tractor, the implement means including at least one transversely extending implement mounting bar; at least one air drill assembly mounted to the implement mounting bar; and container means for the seed or other particulate material to be placed in the ground, the container means including means for creating a positive air pressure to drive seed or other particulate material therefrom to the air drill assembly. The air drill assembly comprises: arm means pivotally connected to the mounting bar; thin, circumferentially sharp disc wheel means rotatably mounted to the arm means at a slight angle to the vertical and at a slight angle to the direction of travel for cutting a narrow furrow in the ground; seed boot means connected to the container means and mounted to the arm means adjacent the disc wheel means and the ground for depositing seed or other particulate material in the furrow; seed lock wheel means mounted to the arm adjacent and behind the disc wheel means for pushing deposited seed or other particulate material deeper into the furrow; and adjustable depth control wheel means for controlling the depth of furrow cut by the disc wheel means, the depth control means being rotatably mounted to one end of a journal member the other end of which is rotatably mounted to the arm means, the journal member including, extending upwardly therefrom, an arcuate portion having a series of equally spaced apart notches therein, the arm means carrying a housing with at least one reciprocable latch member therein, the latch member being engageable with a selected one of the notches to adjust the position of the depth control wheel means relative to the disc wheel means.